Vapor electric device



April 19, 1949. PAKALA 2,467,772

VAPOR ELECTRIC DEVICE Filed May 22, 1948 2 Sheets-Sheet l 5 INVENTOR 7 WITNESSES: 5

William E. Pakala.

\ wlmm ATTOR N EY April 19, 1949. w. E. PAKALA VAPOR ELECTRIC DEVICE 2 Sheets-Sheet 2 Filed May 22, 1948 lNVENTOR Vl zllz'am E. Pakala J1 mm ATTORNEY Patented Apr. 19, 1949 UNITED STATES PATENT QFFICE VAPOR ELECTRIC DEVICE William E. Pakala, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of llennsylvania Application May22, 1948, Serial No. 28,619

5 Glaims. l.

My invention relates to a .vaporelectric device, and particularly to an improved construction for a single anode vapor electric valve.

It is usual that'in the construction ,of electrical apparatus the weight and cost per unitof energy decreases with the increase 'in capacity of the apparatus. Vapor electric devices have heretofore been an exception to this rule, and it has been extremely hardtokeep the weight and cost even to unitary proportions as the power increases. This is due in part tothe fact that vapor electric discharge devices are current devices, and the sizes and proportions increase in proportion to the current, not in proportion to the first power but generally some power higher than the first power. For example,.the anode conduction area and the tube wall cooling area are proportional to the three-halves power of the average current. Also the arc drop increases for the same current density as the tube size was made larger resulting in the need for additional cooling surface per-unit of current. The principal reason for this is that the cooling efliciency, that is,,the cooling of ions and neutral vapor by diffusion to cooling surfaces decreases as the diameter of the device increases.

Heretofore vapor electric devices have been constructed substantially cylindrical in shape as cylindrical containers more readily withstand the high external pressures without excessive weight of material. According to my invention I provide a non-circular container with noncircular anodes, the surfaces of which rapidly increase with increasing proportion of one diameter of the container. I prefer to make the construction of a rectangular box or slot type construction which greatly reduces the diffusion distance from the anode to the cooling surface, and I also reduce the vapor pressures at the fronts of the anode thereby reducing the time that the anode works against a high ion and high vapor density.

It is an object of my invention to provide a vapor electric device having a high cooling efficiency.

It is a further object of my invention to provide a vapor electric device having a low ratio of weight and cost to current capacity.

It is a further object of my invention to provide a substantially rectangular vapor electric device.

It is a further object of my invention to provide a high efiiciency vapor electric device.

Other objects and advantages of my invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing, in which:

Figure l is a sectional elevation of a vapor electric converter according to my invention Fig. 2 is a similar view taken at right angles to the section of Fig. 1; and

Fig. 3 is an enlarged crosssection taken along the line IIIIII of Fig. 2.

In an exemplary embodiment of my invention according to the figures, a vapor electric valve is of the box or slot type comprising a substantially rectangular container l preferably having the side walls 2 slightly arched as at .3 to withstand the external pressure. While the containers i may be formed in any suitable manner, I prefer to form the sides 2 by stampings from individual fiat sheets so that instead of having one longitudinal seam, there will be two complementary seams instead of the conventional one longitudinal seam of the cylindrical container. However, it will be obvious to one skilled in the art that the side walls 2 of the containers I could be forged from one continuous flat sheet with only a single longitudinal seam. The 11913.4 and bottom 5 are likewise forgingsor stampings welded or otherwise secured in the ordinary manner to the side walls 2 of the container i.

In order to provide a high ratio of cooling surface to the cross sectional area of the device, one of the cross sectional axes is considerably longer than the other so that in shape it is an elongated rectangle or slot in cross section. The anode 6 has a cross section shape substantially conforming to the cross section shape of container l. The anode 8 is preferably closely Spaced from the side walls 2 of the container I at least adjacent the top portion 9 thereof, while preferably two or more of the working faces 'l-8 of the anode 6 are tapered from the top 9 of the anode I towards the bottom or working face I'D of the anode 6, whereby the space H between the anode surface and the cooling surface 2 increases from the top 9 of the anode 5 to the working face ID of the anode 6.

Cooperating with the anode t is a pool 12 of liquid cathode material, usually of mercury or some combination thereof, and this pool i2 is preferably of the same shape and size and covers the entire bottom 5 of the container I. However, I prefer to constrict the working surface of the cathode 52 to a substantially annular pool [4 by enclosing a portion i i of the cathode pool [2 by a suitable insulating ring it and initiating the cathode spot within the ring ill by means of any suitable device such as a make-alive or an ignitor electrode l6. Where the device is to be continuously or intermittently excited over any extended period, a keep-alive electrode l! is also provided.

Preferably, a shield l8 conforming substantially in shape to the working face Ill of the anode 6 is interposed between the annular cathode surface l4 and the working face ID of the anode 6. Because of the short difiusion distances II from the anode 6 to the cooling surfaces 2, and the interposition of the bafile l8 between the working surface 14 of the cathode l2 and anode 6, it is usually unnecessary to provide any further shielding between the anode 6 and cathode I4. However, it will be obvious that in certain applications, control or deionizing grids, not shown, will also be required in the space between the anode 6 and the cathode l4.

While for purposes of illustration, I have shown and described a specific construction according to my invention, and described my invention to the best of my present understanding, I wish it to be understood that I am not limited to the example or explanation herein given, and it is apparent that many changes and modifications can be made without departing from the true spirit of my invention or the scope of the appended claims.

I claim as my invention:

1. A vapor electric device comprising a substantially rectangular metallic container and a substantially rectangular anode suspended in closely spaced relation to the side walls of said container.

2. A high efiiciency discharge device comprising an anode having an elongated cross sectional shape, a container substantially conforming in cross section shape to the corresponding cross section of the anode, an elongated cathode pool in said container and a shield interposed between the pool and the end of the anode.

3. A vapor electric valve comprising a metallic container enclosing a cathode pool and an insulated anode, the cross sectional configuration of said container comprising a minor and a major axis, the anode having substantially the same cross sectional shape as the container, said anode being progressively smaller in the direction from the base of the anode toward the cathode whereby the anode is closely spaced from the sides of the container adjacent the base of the anode and progressively departs from the sides of the container toward the tip of the anode facing the cathode.

4. A vapor electric device comprising a substantially fiat sided metallic container, said container being substantially elongated in one lateral dimension, an anode in said container, said anode substantially conforming in shape to the shape of the container, a cathode pool below the anode, and an elongated battle between the pool and the lower face of the anode.

5. A vapor electric device comprising a substantially rectangular metallic container, the substantially fiat sides of said container being arched to withstand atmospheric pressure, a substantially rectangular anode suspended in insulated relation in said container, two oppositely disposed lateral faces of said anode sloping inwardly adjacent the lower end thereof, the sides of said anode being closely spaced from the sides of said container, a pool of cathode material in said container and a substantially rectangular baflle between said pool and the lower face of said anode.

WILLIAM E. PAKALA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,367,987 White Jan. 23, 1945 FOREIGN PATENTS Number Country Date 412,987 Great Britain July 6, 1934 

